Characteristics of ADHD in Children

February 8th, 2009

A diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD) is based on two primary behavioral dimensions, which appear to cut across ethnic and cultural groups: 1) inattention; and 2) hyperactive-impulsive behavior. Put simply, the former is an inability to focus for long periods of time on any task (especially repetitive ones) without becoming distracted, engaging in off-task behavior, or otherwise becoming less productive. An excessive activity level, fidgeting, inability to stay seated when necessary, talking excessively and loudly, interfering with others, and generally acting as if “driven by a motor” characterize hyperactive-impulsive behavior.

While this may describe most young children on occasion, both factors are extreme with those who have ADHD. This behavior may vary according to situation and context (for example, behavior is typically worse later in the day, in the absence of adult supervision, and in more complex situations), and often shows comorbidity with various cognitive abilities. ADHD is diagnosed when a child exhibits six or more each of the Inattention and Hyperactivity-Impulsivity symptoms listed in the APA’s DSM-IV criteria for the disorder.

While ADHD is a very real disorder, the diagnosis is often suspect. Many argue that ADHD is often used as an excuse for parents to medicinally control children who either a) display behavior normal for young children; or b) have been inadequately disciplined in the traditional manner. Many adults have become intolerant of normal childhood behavior and are unwilling to discipline children, so they turn to Ritalin and other ADHD control drugs for surcease.

Prevalence and Gender Difference

Based on parental and teacher descriptions of behavior, the prevalence of ADHD in the juvenile population should be as high as 57%; however, ADHD is clinically diagnosed in only 2-6.3% of children. Younger children are much more likely to be diagnosed with ADHD, with rates falling by as much as half between preschool and the 6-12 year old range, and falling significantly again in adolescence, to 0.9-2% for girls and 1-5.6% for boys. Boys are roughly three times more likely to be diagnosed with ADHD than girls. However, this may be a function of how the diagnostic criteria are applied, especially since the gender differences even out once co-morbid conditions are controlled for.

The fact that ADHD prevalence decreases sharply with age underscores the contention that most accounts of ADHD are the result of adult intolerance for ordinary childhood behavior. Younger kids (especially little boys) are naturally more exuberant and noisy than older children, who are undergoing changes related both to physical maturity and enculturation that encourage more adult behavior. The fact that ADHD prevalence dives sharply at adolescence bolsters this argument.
Developmental Problems Associated with ADHD

These problems add up to poor motor coordination, poor academic performance, persistent social problems, and even reduced intelligence. Health may be compromised by proneness to accidental injury, especially when driving, as well as by sleep disorders.

The developmental problems associated with ADHD are significant and distressing, almost worse than the disorder itself, and this brings home the seriousness of ADHD. While ADHD may not be as prevalent as many parents and teachers would like us to believe, it’s clear that it can be a dangerous and debilitating illness.

Etiologies

The factors thought to be responsible for ADHD are both complex and multitudinous. One theory is that at least some ADHD symptoms are the result of brain damage, since they are similar to those arising from some types of brain infections and trauma. Neurological studies indicate a connection with dysfunction in the frontal lobes, which regulate attention and inhibition. Neurotransmitter deficiencies may also be responsible. Otherwise, some studies link ADHD to pregnancy and birth factors; younger mothers tend to have more ADHD children. ADHD may also have a genetic basis, or may be due to thyroid disorder, environmental toxins, or psychosocial factors.

That ADHD may be caused by a variety of factors, from brain dysfunction to social issues, seems most likely. Too often, researchers try to reduce complex issues to single causes, if only because a single cause would allow for a single “magic pill” solution. However, few things in the human realm — either medical or social — are ever that simple. What we identify as ADHD may be a constellation of related disorders that are lumped together under one term, much as lump together all the dozens of cancers under one term in general conversation. As our understanding of the disorder evolves, it may in the future become possible to discern and define the different types of ADHD based on cause, in a manner more specific than the divisions we use today.

Theoretical Framework

The theoretical framework underlying our current understanding of ADHD remains rather nebulous. Various theories have been put forth, most revolving around defects in behavioral inhibition, deficits in sensitivity to reinforcement, deficits in inattention, arousal, and inhibition in the absence of immediate reward, and neurological explanations for the observed behavior. It is obvious that poor behavioral inhibition is the most important behavioral factor in ADHD.

In light of this, one researcher, Dr. Russell A. Barkley, has developed a hybrid model that includes many of the features of previous ADHD models. His theory explains how behavioral inhibition (self-control) and motor control systems (such as persistence, sensitivity to feedback, and execution of responses) are interrelated to and regulated by four executive functions: working nonverbal memory, working verbal memory, self-regulation of effect/motivation/arousal, and reconstitution (internalization of play). He concludes that ADHD is a disorder of performance, not skill; that is, in their behavior ADHD sufferers are unable to apply previously learned knowledge (especially in the social behavior realm) to new situations, even though, at some level, they may realize exactly what they should do in such situation.

He suggests various ways to treat ADHD patients, both pharmaceutically and otherwise, especially in regards to making actions and their consequences more temporally contiguous. For the ADHD sufferer, punishment or reward must be immediate to be effective, since those with serious ADHD suffer from what Barkley calls a “myopia or blindness to time.” They do not see or understand distances that lie ahead in time.

The key to his theory is the concept of temporal blindness or myopia. Those of us without symptoms of ADHD can see ahead to the future; we not only see what we need to do to reach our goals or maintain the status quo, but have also internalize
d the concept of personal accountability. We understand the consequences of our actions, both good and bad. People with ADHD often do not, or are unable to apply the rules they have learned, and so may be blindsided by future events that others, with a minimum of personal inhibition, might have avoided. This theory seems make imminent sense, though of course the true test of Barkley’s theory is how well it fits the clinical reality of ADHD, and how well it stands the tests of time.